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 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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package java.rmi.registry;

import java.rmi.AccessException;
import java.rmi.AlreadyBoundException;
import java.rmi.NotBoundException;
import java.rmi.Remote;
import java.rmi.RemoteException;

/**
 * <code>Registry</code> is a remote interface to a simple remote
 * object registry that provides methods for storing and retrieving
 * remote object references bound with arbitrary string names.  The
 * <code>bind</code>, <code>unbind</code>, and <code>rebind</code>
 * methods are used to alter the name bindings in the registry, and
 * the <code>lookup</code> and <code>list</code> methods are used to
 * query the current name bindings.
 *
 * <p>In its typical usage, a <code>Registry</code> enables RMI client
 * bootstrapping: it provides a simple means for a client to obtain an
 * initial reference to a remote object.  Therefore, a registry's
 * remote object implementation is typically exported with a
 * well-known address, such as with a well-known {@link
 * java.rmi.server.ObjID#REGISTRY_ID ObjID} and TCP port number
 * (default is {@link #REGISTRY_PORT 1099}).
 *
 * <p>The {@link LocateRegistry} class provides a programmatic API for
 * constructing a bootstrap reference to a <code>Registry</code> at a
 * remote address (see the static <code>getRegistry</code> methods)
 * and for creating and exporting a <code>Registry</code> in the
 * current VM on a particular local address (see the static
 * <code>createRegistry</code> methods).
 *
 * <p>A <code>Registry</code> implementation may choose to restrict
 * access to some or all of its methods (for example, methods that
 * mutate the registry's bindings may be restricted to calls
 * originating from the local host).  If a <code>Registry</code>
 * method chooses to deny access for a given invocation, its
 * implementation may throw {@link java.rmi.AccessException}, which
 * (because it extends {@link java.rmi.RemoteException}) will be
 * wrapped in a {@link java.rmi.ServerException} when caught by a
 * remote client.
 *
 * <p>The names used for bindings in a <code>Registry</code> are pure
 * strings, not parsed.  A service which stores its remote reference
 * in a <code>Registry</code> may wish to use a package name as a
 * prefix in the name binding to reduce the likelihood of name
 * collisions in the registry.
 *
 * @author Ann Wollrath
 * @author Peter Jones
 * @see LocateRegistry
 * @since JDK1.1
 */
public interface Registry extends Remote {

  /**
   * Well known port for registry.
   */
  public static final int REGISTRY_PORT = 1099;

  /**
   * Returns the remote reference bound to the specified
   * <code>name</code> in this registry.
   *
   * @param name the name for the remote reference to look up
   * @return a reference to a remote object
   * @throws NotBoundException if <code>name</code> is not currently bound
   * @throws RemoteException if remote communication with the registry failed; if exception is a
   * <code>ServerException</code> containing an <code>AccessException</code>, then the registry
   * denies the caller access to perform this operation
   * @throws AccessException if this registry is local and it denies the caller access to perform
   * this operation
   * @throws NullPointerException if <code>name</code> is <code>null</code>
   */
  public Remote lookup(String name)
      throws RemoteException, NotBoundException, AccessException;

  /**
   * Binds a remote reference to the specified <code>name</code> in
   * this registry.
   *
   * @param name the name to associate with the remote reference
   * @param obj a reference to a remote object (usually a stub)
   * @throws AlreadyBoundException if <code>name</code> is already bound
   * @throws RemoteException if remote communication with the registry failed; if exception is a
   * <code>ServerException</code> containing an <code>AccessException</code>, then the registry
   * denies the caller access to perform this operation (if originating from a non-local host, for
   * example)
   * @throws AccessException if this registry is local and it denies the caller access to perform
   * this operation
   * @throws NullPointerException if <code>name</code> is <code>null</code>, or if <code>obj</code>
   * is <code>null</code>
   */
  public void bind(String name, Remote obj)
      throws RemoteException, AlreadyBoundException, AccessException;

  /**
   * Removes the binding for the specified <code>name</code> in
   * this registry.
   *
   * @param name the name of the binding to remove
   * @throws NotBoundException if <code>name</code> is not currently bound
   * @throws RemoteException if remote communication with the registry failed; if exception is a
   * <code>ServerException</code> containing an <code>AccessException</code>, then the registry
   * denies the caller access to perform this operation (if originating from a non-local host, for
   * example)
   * @throws AccessException if this registry is local and it denies the caller access to perform
   * this operation
   * @throws NullPointerException if <code>name</code> is <code>null</code>
   */
  public void unbind(String name)
      throws RemoteException, NotBoundException, AccessException;

  /**
   * Replaces the binding for the specified <code>name</code> in
   * this registry with the supplied remote reference.  If there is
   * an existing binding for the specified <code>name</code>, it is
   * discarded.
   *
   * @param name the name to associate with the remote reference
   * @param obj a reference to a remote object (usually a stub)
   * @throws RemoteException if remote communication with the registry failed; if exception is a
   * <code>ServerException</code> containing an <code>AccessException</code>, then the registry
   * denies the caller access to perform this operation (if originating from a non-local host, for
   * example)
   * @throws AccessException if this registry is local and it denies the caller access to perform
   * this operation
   * @throws NullPointerException if <code>name</code> is <code>null</code>, or if <code>obj</code>
   * is <code>null</code>
   */
  public void rebind(String name, Remote obj)
      throws RemoteException, AccessException;

  /**
   * Returns an array of the names bound in this registry.  The
   * array will contain a snapshot of the names bound in this
   * registry at the time of the given invocation of this method.
   *
   * @return an array of the names bound in this registry
   * @throws RemoteException if remote communication with the registry failed; if exception is a
   * <code>ServerException</code> containing an <code>AccessException</code>, then the registry
   * denies the caller access to perform this operation
   * @throws AccessException if this registry is local and it denies the caller access to perform
   * this operation
   */
  public String[] list() throws RemoteException, AccessException;
}
